International Journal of Modern Physics B

This paper reviews our recent research on nonlinear dynamics of microchip solid-state lasers subjected to delayed optical feedback. Instabilities in two types of physical systems including multimode lasers with feedback and lasers with frequency-shifted feedback are discussed. Applications of microchip lasers with feedback to shot-noise-limited self-mixing optical sensing and imaging are summarized.

A non-relativistic plasma model endowed with an "exotic" structure associated with the two-parameter central extension of the planar Galilei group is constructed. Introducing a Chern–Simons statistical gauge field provides us with a self-consistent system; when the magnetic field takes a critical value determined by the extension parameters, the fluid becomes incompressible and moves collectively, according to the Hall law.

Ordered phase for the antiferromagnetic Potts model is a controversial problem. For the three state Potts model, whether the phase just below the antiferromagnetic transition temperature is rotationally symmetric or not has not been settled. This comes from subtle free energy structure near the phase transition. Numerical simulations can be hampered by the subtlety because of finite size effects. Necessary size of systems for simulations to distinguish possible ordered states is estimated by solving self-consistent equations within the pair approximation to obtain free energies of ordered states and saddle points between them.

The cascade rate of passive scalar and Bachelor's constant in scalar turbulence are calculated using the flux formula. This calculation is done to first order in perturbation series. Batchelor's constant in three dimension is found to be approximately 1.25. In higher dimension, the constant increases as d^1/3.

We give an extensive analytical study of a class of linear growth equations in 1+1 dimensions which describe certain interfacial super-roughening processes. With our calculation, we give a first rigorous analytical affirmation on the applicability of the anomalous dynamic scaling ansatz, which has been proposed to describe the dynamics of super-rough interfaces in finite systems. In addition, we explicitly evaluate not only the leading order but also all the sub-leading orders which dominate over the ordinary dynamic scaling term. Finally, we briefly discuss the influence of the macroscopic background formation on the interfacial anomalous roughening in super-rough growth processes.

Foreman and Lomer proposed in 1957 a method of estimating the harmonic forces between parallel planes of atoms of primitive cubic crystals by Fourier transforming the squared frequencies of phonons propagating along principal directions. A generalized form of this theorem is derived in this paper and it is shown that it is more appropriate to apply the method to certain combinations of the phonon dispersion relations rather than to individual dispersion relations themselves. Further, it is also shown how the method may be extended to the hexagonal close packed and diamond lattices. Explicit, exact and general relations in terms of atomic force constants are found for deviations from the Blackman sum rule which itself is shown to be derived from the generalized Foreman–Lomer theorem.

By making slight changes of the Nagel–Schreckenberg model, we propose a varied model for a realistic description of the traffic flow on single-lane highways. While the NaSch model fails to cover the "takeover", this realistic situation gets a good description in our model. Moreover, from the fundamental diagrams achieved in our model, we can divide the forms of traffic flow into five different modes, which are obviously observed in their corresponding time-space diagrams. We also make a comparison of the results of a simple kind of mean-field approximation and the cellular automaton approach.

The X-ray photo-emission spectroscopy (XPS) measurements have been performed on Sm_0.85Nd_0.15Se. The results have shown that the Sm ion in the compound is existing in divalent state and there is no inter configuration mixing (ICF). Theoretically calculated valence also supports the conclusion drawn from XPS studies.